How to link workItem in one project area to workitem in other project area using participant plugin

You can find some information in the link API here: http://rsjazz.wordpress.com/2012/09/20/the-rtc-workitem-server-link-api-linking-to-work-items-and-other-elements/

I haven't tried that yet, but IWorkItemServer provides a way to create a work item in the server API. You probably need to work with the WorkingCopy as described here http://rsjazz.wordpress.com/2012/11/27/resolve-parent-if-all-children-are-resolved-participant/ and here http://rsjazz.wordpress.com/2012/07/31/rtc-update-parent-duration-estimation-and-effort-participant/ .

Hi Nikhil,

this is how the code for creating and linking a work item would look like.
How you would find the owner would depend on your scenario and can get quite complex. I am about to blog about a participant to create an approval but won't be able to make it next week. The code below is the simple scenario where you know the owner ID.

	private IWorkItem createWorkItem(String projectAreaName, String workItemType,
			String categoryName, String summary, String owner, IProgressMonitor monitor)
			throws TeamRepositoryException {
		URI uri = URI.create(projectAreaName.replaceAll(" ", "%20"));
		IProcessArea processArea = fAuditableCommon.findProcessAreaByURI(uri, null, monitor);
		IProjectAreaHandle projectArea=processArea.getProjectArea();
		IWorkItemType type = fWorkItemCommon.findWorkItemType(projectArea, workItemType, monitor);

		List path = Arrays.asList(categoryName.split("/"));

		IWorkItem newWorkItem = fWorkItemServer.createWorkItem2(type);
		ICategoryHandle category = fWorkItemCommon.findCategoryByNamePath(projectArea, path, monitor);
		newWorkItem.setCategory(category);
		newWorkItem.setHTMLSummary(XMLString.createFromPlainText(summary));
		newWorkItem.setOwner(getContributorByID(owner));
		IStatus status = fWorkItemServer.saveWorkItem2(newWorkItem, null, null);
		if (!status.isOK()) {
			return null;
		}
		return newWorkItem;	
	}
	
	private IContributorHandle getContributorByID(
			String approverId) throws TeamRepositoryException {
		/**
		 * Get Approver Handle by searching some external system Replace this
		 * with some code to query the external system.
		 */
		IContributorService contributorService = getService(IContributorService.class);
		IContributorHandle approver = contributorService
				.fetchContributorByUserId(approverId);
		return approver;
	}

	
	/**
	 * Link two work items as blocking
	 * 
	 * @param blockingWorkItem
	 * @param blockedWorkItem
	 * @throws TeamRepositoryException
	 */
	private void linkBlockingWorkItems(IItemHandle blockingWorkItem,
			IItemHandle blockedWorkItem) throws TeamRepositoryException {
		/**
		 * Creating Links on the Server.
		 * 
		 * @see: 
		 *       https://jazz.net/forum/questions/82384/serverside-create-link-from
		 *       -a-workitem-to-a-changeset
		 * @see: 
		 *       https://jazz.net/forum/questions/80731/how-do-i-create-an-included
		 *       -in-build-link-from-java-api/80781
		 */

		IReferenceFactory refFactory = IReferenceFactory.INSTANCE;
		IReference source = refFactory.createReferenceToItem(blockingWorkItem);
		IReference target = refFactory.createReferenceToItem(blockedWorkItem);
		ILinkService linkService = getService(ILinkService.class);
		ILinkServiceLibrary linkServiceLibrary = (ILinkServiceLibrary) linkService
				.getServiceLibrary(ILinkServiceLibrary.class);

		ILink link = linkServiceLibrary.createLink(
				WorkItemLinkTypes.BLOCKS_WORK_ITEM, source, target);
		linkServiceLibrary.saveLink(link);
	}

            fAuditableCommon = getService(IAuditableCommon.class);
            fWorkItemCommon = getService(IWorkItemCommon.class);

        String projectAreaName="DevProject";
        String categoryName = "Dev1";
        String workItemType = "defect";
        String summary = "Test";
        String owner = "TestJazzGuest1";

        IWorkItem newWorkItem = createWorkItem(projectAreaName, workItemType, categoryName, summary, owner,
                monitor);
        if(newWorkItem!=null){
            linkBlockingWorkItems(newWorkItem, newState);
            return;
        }
        String description = "Failed to create and link work item.";
        IReportInfo info = collector.createInfo(
                "Unable to update Parent state.", description);
        info.setSeverity(IProcessReport.ERROR);
        collector.addInfo(info);

Decided to get the approval participant posted right away. Maybe an inspiration for you how to find the owner for the work item.